Accurate alignment of closure configurations in packaging is required for various operations such as to control the opening of containers with safety caps or to ensure the proper operation of liquid dispensing mechanisms attached to or incorporated in caps or bottles. U.S. Pat. No. 3,261,315 is an example of a closure configuration where specific alignment of the cap closure is required for the dispensing of liquids. Also of concern in closure configurations is the method used to open and close the containers such as axial snapping on and off or twisting and untwisting. Consumers are familiar with the rotatable motion for closing or removing caps, and therefore with reusable containers a twisting or untwisting capability is most desirable. However, in regard to the closing of containers by automated machines, a simple axial snap-on movement in which the closure is aligned with respect to the container is preferable. In addition, no rotational motions are required which makes for simplified, automated assembly. Also, for some people with physical handicaps, a twisting motion is impossible, while a snap-on, snap-off motion is not. Therefore, the ideal cap is one which is versatile enough to provide the ability to use either method for opening and closing. U.S. Pat. No. 3,223,269 discloses a cap which may be snapped on and then removed and replaced by the same rotatable motion that is a feature of all screw caps. Other snap-on or twist-off caps are described in U.S. Pat. Nos. 4,298,129 and 3,910,444.
Unfortunately, none of the aforementioned prior art closure configurations incorporate the versatility of the combined opening and closing methods with ensured, accurate alignment. In addition, none of these prior cap closures provide the advantage of being able to be snapped off as well as snapped on and twisted off and on.
Other important considerations in packaging are the production costs and design efforts involved in manufacturing different moldings. A cap which may be used interchangeably both as a removable or irremovable closure is also highly advantageous. This is especially so when such a design configuration still provides accurate alignment and only requires changes in the container neck moldings to be either removable or irremovable.